Nutrition is the single most important environmental factor affecting health worldwide. In the developing countries, inadequate nutrition is a cause of a variety of deficiency diseases generally associated with increased rates of infection. In the developed countries, over nutrition plays a role in the pathogenesis of a variety of chronic degenerative diseases, including coronary heart disease, hypertension, obesity, diabetes, and probably cancers of the breast and colon. This broad topic of nutritional resources and human disease cannot be considered without considering the food/population problem. The extent to which one sees manifestations of deficiency disease or the diseases of under nutrition, as opposed to the diseases of over nutrition, generally depends upon the food/population ratio. When food is scarce and the population large, nutritional deficiency disease is common. Contrariwise, when the food supply is ample for a given population group, the nutrition-related degenerative diseases are prevalent. It is also true that in those areas of the world characterized by under nutrition, there are always pockets of over nutrition where the food supply per individual in a given group or class is high. In the United States, which is generally considered to be a zone of affluence and high food resources, there are pockets of under nutrition that are characterized by poverty and a high population/food ratio.
Climax ecology is well known to ecologists as the final steady state in a given ecological system. As regards this steady state in "old" countries, the F/P ratio is low, the percentage of total time spent on food production is high (as much as 90%), the diet is high in cereals and low in protective nutrients, birth and death rates are both high, life expectancy is short, social stability is great, poverty is nearly universal and starvation and nutritional deficiency disease are common...................
